/**
*      author: Y_Yao
*      created: 2024-11-22 12:20:14
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 1e18;
const int INF = 0x3f3f3f3f;
const int N = 20 + 7;
int a[N];
int n;

void solve()
{
    cin >> n;
    map<int,int> hash;
    for(int i = 1;i <= n;i++)
    {
        cin >> a[i];
        hash[a[i]]++;
    }

    int ret = 0;
    for(auto e : hash)
    {
        ret += e.second / 2;
    }

    cout << ret << endl;

}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}